The invention relates to an electronically commutated electric machine with a stator housing which receives a stator in a stator chamber and delimits the latter with respect to a rotor chamber receiving a rotor.
Electronically commutated, i.e. brushless, motors are increasingly used, in particular in automobile engineering. Brushless motors of this type are used, for example, as drives for water pumps. In particular in application cases of this type, motors of this type have a stator housing which receives a stator in a stator chamber provided for this purpose, wherein a delimitation with respect to a rotor chamber is provided; accordingly, the stator is completely enclosed and is partitioned off from the rotor and from the surroundings. In order to be able to fit arrangements of this type, the individual components have to have a certain amount of play. However, once installation is finished, the components are intended to be mounted in a play-free manner with respect to one another in order to achieve a vibration-free formation of the arrangement and in order to be able to avoid an increased noise level due to insufficient damping or rattling noises. In the prior art, this freedom from play is achieved only by complicated and not easily controllable additional measures, for example screwing, potting or adhesively bonding the individual components together. Although this can result in a play-free arrangement, the complete absence of play causes a problem for the thermal expansion of the components, in particular during long-term operation. The measures known in the prior art, such as, in particular, potting and adhesive bonding, are stressed over time due to the different thermal expansion of individual components and, in unfavorable cases, may fail over a relatively long operating period and, in particular, adhesive bonds or potting means may tear, as a result of which the arrangement may become untight, which may result in component failure.